John Slattery, who plays Roger Sterling on AMC’s Mad Men, talks about the trick to juggling on-camera and his theory on what the show is all about.

Q: You juggle, Ken tap dances; any other hidden talents lurking within the cast of Mad Men that haven’t made it to the screen?

A: I’m sure [Jon] Hamm has a whole raft of talents. He’s one of those guys that can do anything… Juggling is pretty easy. It looks harder than it is. The hard thing about it is doing it when the camera is turned on and not screwing it up long enough to say the line… Aaron Staton’s tap-dancing, that was really impressive. Tap dancing with the cane and the eye patch. [Laughs] That’s not easy. He was dancing with one leg and one eye.

Q: You directed “A Tale of Two Cities,” the episode at a pool party in the Hollywood hills. What was the most memorable part of directing that episode?

A: It was raining torrentially. It was literally three solid days of rain, so what you see there is actually kind of a miracle… Whenever it would stop raining, we’d run outside the house and shoot whatever we could and made it look like it was a beautiful day in Hollywood. It was actually a really s—-y day in Encino. [Laughs]… There were 50 or 60 extras, and I was acting in it at the same time. It was a lot…

Q: Yet you laugh about it…

A: The whole thing made me laugh. The writing was so funny, from the plane ride out there to Rich Sommer’s character pulling up in the car, was to me just hilarious, and Danny Strong… We also got to use a Steadicam for the first time in the show’s history. We’ve never done that. And we pitched the idea to Matthew Weiner because Don had that whole trippy hash scene where he sees Megan and then they go walking and then he bumps into the soldier and all that.

Q: Roger had a great monologue last season about life being a series of doorways to nowhere. What were your thoughts when you read that scene?

A: Every character in the show has had a moment like that when they go, “This is what my life is,” or, “This is who I am.” They’ve all had those moments on the show — Christina [Hendricks]’s character and Elisabeth Moss’s character and Pete Campbell — moments where you wonder if this is all there is. Or they think, “I thought that I’d be happier. Why am I not?”… And I think that’s what the show is about.

Q: Roger has changed a great deal over the course of the series. Has his journey changed you at all?

A: This thing has changed our lives in ways that none of us could have imagined. It’s given us opportunities that none of us could have imagined. For that, I will always be indebted to Matthew Weiner. Sometimes, specifically speaking of a character, you do something and then you realize, “Oh, I’ve done this in front of the camera, I probably shouldn’t do that in real life.” But it doesn’t always cross over into real life as much as the audience thinks it might.

Q: Roger’s relationship with Joan has changed so much over time. Are you curious how it will all end?

A: This show is so unpredictable. The table read is very exciting because nobody really knows what the hell is going to happen, and I’ve stopped trying to guess what Matthew Weiner is going to do because I’m never right. And it’s always better than you think it’s going to be.

Q: Being a father yourself, do you have any parenting advice for Roger?

A: This is his second chance. I would probably say look at what he did the first time and do something different. [Laughs] Whatever you do, don’t do what you did before.